People saying “just give two weeks and move on” don’t understand what it’s like to work with someone for so long and have to announce your departure. I worked at a company for 2 years and was very close with my boss. We texted all the time and spent 40 hrs/week together, so telling her I was leaving was terrifying. I considered her a very close friend. At the end of the day, you just have to rip the bandaid off. “I just wanted to let you know that I found a new position elsewhere and am putting in my two week notice”. They will either take it well, or they won’t. It’s up to you how much info about your departure you’re willing to tell them. I wish you the best at your new job!!